U.S. patent application number 14/853436 was filed with the patent office on 2016-01-07 for irrigation system and method.
The applicant listed for this patent is International Business Machines Corporation. Invention is credited to Hendrik F. Hamann, Levente I. Klein, Sergio A. Bermudez Rodriguez, Michael A. Schappert.
Application Number | 20160000023 14/853436 |
Document ID | / |
Family ID | 51486627 |
Filed Date | 2016-01-07 |
United States Patent
Application |
20160000023 |
Kind Code |
A1 |
Hamann; Hendrik F. ; et
al. |
January 7, 2016 |
IRRIGATION SYSTEM AND METHOD
Abstract
An irrigation system is provided and includes a main irrigation
line, one or more lateral driplines, each lateral dripline being
divided into zones and including a plurality of emitters at each
zone and a plurality of controllable valves disposed along each of
the one or more lateral driplines at zone borders. Each one of the
plurality of controllable valves is actuatable to activate
corresponding emitters in the associated zone in a zone by zone
cycle and each one of the plurality of emitters is replaceable to
vary an amount of deliverable fluid by the zone by zone cycle.
Inventors: |
Hamann; Hendrik F.;
(Yorktown Heights, NY) ; Klein; Levente I.;
(Tuckahoe, NY) ; Rodriguez; Sergio A. Bermudez;
(Hudson, NY) ; Schappert; Michael A.; (Wappingers
Falls, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
International Business Machines Corporation |
Armonk |
NY |
US |
|
|
Family ID: |
51486627 |
Appl. No.: |
14/853436 |
Filed: |
September 14, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13792757 |
Mar 11, 2013 |
9167757 |
|
|
14853436 |
|
|
|
|
Current U.S.
Class: |
239/542 |
Current CPC
Class: |
B05B 12/04 20130101;
A01G 25/162 20130101; A01G 25/02 20130101; A01G 25/16 20130101 |
International
Class: |
A01G 25/02 20060101
A01G025/02; A01G 25/16 20060101 A01G025/16 |
Claims
1. An irrigation system, comprising: lateral driplines respectively
divided into multiple zones along respective lengths thereof and
including emitters at each of the multiple zones; and controllable
valves disposed remotely from the emitters along each respective
length of each lateral dripline at zone borders between the
multiple zones with the emitters at each multiple zone being
non-inclusively between sequential controllable valves, the
controllable valves being actuatable to activate corresponding
emitters in the associated zone.
2. The irrigation system according to claim 1, wherein the
controllable valves comprise solenoid valves.
3. The irrigation system according to claim 1, further comprising a
control station configured to selectively actuate each controllable
valve.
4. The irrigation system according to claim 1, wherein multiple
lateral driplines are associated with same zones.
5. The irrigation system according to claim 1, wherein each emitter
has a same emission rate.
6. The irrigation system according to claim 1, wherein the emitters
in zones remote from a main irrigation line have higher emission
rates than emitters in zones proximate to the main irrigation
line.
7. The irrigation system according to claim 6, wherein the emitters
in the zones remote from the main irrigation line are activated for
a shorter time than the emitters in the zones proximate to the main
irrigation line.
Description
DOMESTIC PRIORITY
[0001] This application is a Continuation of U.S. application Ser.
No. 13/792,757, which was filed Mar. 11, 2013. The entire
disclosures of U.S. application Ser. No. 13/792,757 are
incorporated herein by reference.
BACKGROUND
[0002] The present invention relates to an irrigation system and
method and, more specifically, to an irrigation system and method
in which lateral driplines are divided into zones with a plurality
of emitters that are activated in a zone by zone cycle.
[0003] Current drip irrigation systems are often equipped with
pressure compensated emitters that can deliver a certain amount of
water to nearby areas based on the fabrication characteristics of
the emitters. Typically, the emitters will have a watering rate of
0.5, 1 or 2 gallons per hour delivery. The amount is set in the
fabrication process or they can be set manually in the field. This
can present problems, however, because industry frequently demands
that drip irrigation systems be able to dynamically adjust the
amount of water that is delivered to a specific location based on
real time information (satellite imagery, field deployed soil
moisture sensor, thermal imagery) of the water absorbed/transpired
by canopy and water evaporation from soil or soil water rentention
properties.
[0004] Current approaches to the problem of using emitters with a
predefined watering rate in a drip irrigation system in which
dynamic adjustments are required rely on delivery of the same
amount of water in every location where the amount of water is
defined as the upper amount required by the most water demanding
spot. The inherent differences in soil properties and crop
characteristics can thus lead to overwatering in many locations
based on such uniform water delivery. Potentially, different rate
emitters can be installed in different locations but temporal
changes in the irrigation schedule does not permit dynamic
adjustments over time.
SUMMARY
[0005] According to one embodiment of the present invention, an
irrigation system is provided and includes a main irrigation line,
one or more lateral driplines, each lateral dripline being divided
into zones and including a plurality of emitters at each zone and a
plurality of controllable valves disposed along each of the one or
more lateral driplines at zone borders. Each one of the plurality
of controllable valves is actuatable to activate corresponding
emitters in the associated zone in a zone by zone cycle and each
one of the plurality of emitters is replaceable to vary an amount
of deliverable fluid by the zone by zone cycle.
[0006] According to another embodiment, an irrigation system is
provided and includes a main irrigation line, one or more lateral
driplines, each lateral dripline being divided into zones and
including a plurality of emitters at each zone and a plurality of
controllable valves disposed along each of the one or more lateral
driplines at zone borders. Each one of the plurality of
controllable valves is actuatable to activate corresponding
emitters in the associated zone in a zone by zone cycle. Each one
of the plurality of emitters at each zone is replaceable by another
emitter with a different emission rate such that a variable amount
of water can be delivered to by the zone by zone cycle.
[0007] According to yet another embodiment, a method of operating
an irrigation system is provided. The method includes coupling one
or more lateral driplines to a main irrigation line, dividing each
lateral dripline into zones and providing each lateral dripline
with a plurality of replaceable emitters at each zone, disposing a
plurality of controllable valves along each of the one or more
lateral driplines at zone borders and actuating each one of the
plurality of controllable valves to thereby activate corresponding
emitters in the associated zone.
[0008] Additional features and advantages are realized through the
techniques of the present invention. Other embodiments and aspects
of the invention are described in detail herein and are considered
a part of the claimed invention. For a better understanding of the
invention with the advantages and the features, refer to the
description and to the drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0009] The subject matter which is regarded as the invention is
particularly pointed out and distinctly claimed in the claims at
the conclusion of the specification. The forgoing and other
features, and advantages of the invention are apparent from the
following detailed description taken in conjunction with the
accompanying drawings in which:
[0010] FIG. 1 is a schematic view of a drip irrigation system;
[0011] FIG. 2A is a side view of a controllable emitter with a
solenoid coil and a magnetic stopper in accordance with
embodiments;
[0012] FIG. 2B is a side view of a controllable emitter with a
solenoid coil and a magnetic stopper in accordance with
embodiments;
[0013] FIG. 3 is a perspective view of a magnetic stopper in
accordance with alternative embodiments; and
[0014] FIG. 4 is a schematic illustration of a magnetic stopper in
accordance with further alternative embodiments;
[0015] FIG. 5 is a side view of a controllable emitter with a
solenoid coil and a magnetic stopper in accordance with alternative
embodiments;
[0016] FIG. 6 is a side schematic view of an irrigation system in
accordance with alternative embodiments;
[0017] FIG. 7 is an enlarged side view of a T-junction of the
irrigation system of FIG. 6;
[0018] FIG. 8A is a side schematic view of an irrigation system in
accordance with further alternative embodiments;
[0019] FIG. 8B is a top down view of an irrigation system;
[0020] FIG. 9A is a schematic view of an irrigation system in
accordance with alternative embodiments; and
[0021] FIG. 9B is a schematic view of a hierarchy of irrigation
system control in accordance with embodiments.
DETAILED DESCRIPTION
[0022] A controllable emitter is provided. The controllable emitter
can be deployed in, for example, a drip irrigation system and
allows a variable of amount of water to be delivered to a specific
location of the drip irrigation system over a period of time. The
controllable emitter includes a solenoid coil slid over a tubular
element that drips the water. The upper part of the tubular element
is normally blocked by a magnetic stopper in the shape of a sphere
or a cone. When a current is applied to the solenoid coil, the
solenoid coil creates a magnetic field that forces the magnetic
stopper to move out of the blocking position and thereby allows
water to flow through the tube. The current applied to the solenoid
coil can be direct current (DC), such that the magnetic stopper may
be displaced continuously, or alternating current (AC), such that
the magnetic stopper may be displaced periodically. The solenoid
coil may be electrically coupled to an electronic circuit that
contains a microcontroller that can receive a command from an
external device and a memory unit on which schedule and timing
information of the magnetic stopper movement is stored. Each
controllable emitter of a given drip irrigation system can be
addressed individually and a specific schedule can be uploaded
wirelessly or over a wireless network into the memory unit such
that each emitter can have an independent schedule. By keeping the
magnetic stopper in a position where water can flow through the
tubular element and timing the period it allows the water to flow
combined with a feedback mechanism that measures water flow, the
amount of delivered water can be determined by the microcontroller.
The system will thus deliver variable amounts of water to any
location subject to the drip irrigation system by uploading an
individual watering schedule.
[0023] A system and method for applying variable amounts of water
or fertilizer over a region, such as agricultural land, using a
drip irrigation system is also provided. The system and method
include installation of drip irrigation lines along a diverter line
such that the water used for irrigation is allowed or restricted to
pass through the lateral drip irrigation line using a T-junction.
The T-junction has a solenoid valve and a check valve. The lateral
drip irrigation lines can be assembled in variable length segments
and the filling of the drip irrigation lines with water can be
controlled using the T-junction and the diverter line. By
controlling the solenoid valves, an amount of fluid, fertilizer or
chemicals delivered to an associated area can be controlled by
adjusting the time the solenoid valves are open and knowing the
number of corresponding emitters and their respective emission
rates.
[0024] In addition, an automated method of controlling valves to
apply variable amounts of water or fertilizer over an extended
agricultural land is provided and uses a minimized modification to
an existing dripline system. The method takes advantage of the
concept that the same amount of water from a central line can be
delivered either by using emitters/nozzles that have higher
emission rates (gallons per hour) and requiring less watering time
or extending the watering time of emitter/nozzles that have lower
emission rates. The approach proposes to install on/off solenoid
valves along a dripline to control water flow and using emitters
that have different emission rates along the line. The higher
emission rate emitters/nozzles are positioned farther from the main
water distribution line while smaller emission rate
emitters/nozzles will be closer to the main water distribution
line. The emitters are inserted such that their emission rate
increases from low to high along the line with the low emission
rate emitters being positioned closer to the main water
distribution line. Thus, by controlling the solenoid valve
open/closed position for different periods of time, the amount of
water delivered to a specific location can be increased or
decreased.
[0025] In all embodiments described above, power can be derived
from a power line or form solar paneling. Certain aspects of the
timing may be affected and determined by the availability and costs
of such power.
[0026] With reference now to FIG. 1, an exemplary drip irrigation
system 10 is provided. The drip irrigation system 10 may be
deployed over a relatively large area, such as a farm or a field
that requires a predefined amount of water delivery above and
beyond the amount provided as atmospheric accumulation. The drip
irrigation system 10 may include multiple drip lines 11, a
plurality of emitters that can be controllable emitters 12 disposed
along each of the multiple drip lines 11, a fluid source 13 and a
control station 14. Each of the multiple drip lines 11 is fluidly
coupled to the fluid source 13 wherein the fluid source 13 provides
a fluid, such as water, to each of the multiple drip lines 11 as a
pressurized fluid.
[0027] The provision of pressurized fluid to each of the multiple
drip lines 11 may, in some cases, be pressure controlled while the
plurality of emitters (i.e., the controllable emitters 12) can be
pressure compensated.
[0028] The control station 14 may be embodied as a computing device
140 having a processing unit 141, memory units 142 and an actuator
unit 143. The processing unit 141 may be electrically coupled via
the actuator unit 143 to each of the plurality of controllable
emitters 12 distributed across the field to thereby provide for
effective local control commands to the controllable emitters 12.
The processing unit 141 is thus configured to cause each of the
plurality of controllable emitters 12 to be actuated and to allow
the pressurized fluid to drip independently of one another. The
memory units 142 have instructions stored thereon, which, when
executed, cause the processing unit 141 to operate in accordance
with the methods described herein.
[0029] With reference to FIGS. 2A and 2B, each of the plurality of
controllable emitters 12 may include a container 20, which is
fluidly coupled to the corresponding drip line 11, a magnetic
stopper 30 and a controllable actuator 40. The container 20
includes a body 21 that is formed as a tubular element to define an
interior 210, an inlet 22 through which the pressurized fluid is
receivable in the interior 210 from the corresponding drip line 11
and an outlet 23 through which the pressurized fluid is exhaustible
from the interior 210. As shown in FIGS. 2A and 2B, the
corresponding drip line 11 may be disposed in a substantially
horizontal orientation (i.e., it extends along a plane of the
irrigated region) wherein the container 20 extends in a
substantially vertical (i.e., downward) orientation.
[0030] The magnetic stopper 30 is normally disposable in a first
position (see FIG. 2A) such that the magnetic stopper 30 prevents a
flow of the pressurized fluid through the inlet 22 and the outlet
23. The magnetic stopper 30 is also actively disposable in a second
position (see FIG. 2B) such that the magnetic stopper 30 permits
the flow of the pressurized fluid through the inlet 22 and the
outlet 23. That is, in the embodiment of FIGS. 2A and 2B, the
magnetic stopper 30 experiences a downward pressure due to the
pressurized fluid and a gravitational force in the substantially
vertical direction. Thus, with the container 20 extending
substantially vertically downwardly from the corresponding drip
line 11, the magnetic stopper 30 normally sits in the inlet 22. In
this condition, the magnetic stopper 30 has sufficient size (i.e.,
diameter) to block the flow of the pressurized fluid through the
inlet 22 and the outlet 23. However, when the magnetic stopper 30
is urged to move toward the second position, the magnetic stopper
30 ceases to block the flow of the pressurized fluid through the
inlet 22 and the outlet 23.
[0031] With reference to FIGS. 2A, 2B, 3 and 4, the magnetic
stopper 30 may be provided in various shapes and sizes. For
example, as shown in FIGS. 2A and 2B, the magnetic stopper 30 may
be a spherical ball-shaped element 31 formed of ferro-magnetic
material. As another example, as shown in FIG. 3, the magnetic
stopper 30 may be a conical element 32 formed of ferro-magnetic
materials. In each case, the container 20 may further include a
porous support element 24 that is coupled to the body 21 at the
inlet 22. The porous support element 24 may be substantially
frusto-conical and serves to maintain a lateral position of the
magnetic stopper 30 when the magnetic stopper 30 is urged to move
toward the second position so that the magnetic stopper 30 can be
reliably returned to the first position.
[0032] As yet another example, as shown in FIG. 4, the magnetic
stopper 30 may be a spherical ball-shaped element 31, which is
formed to define a bore-hole 310. The bore-hole 310 extends from
one side of the spherical ball-shaped element 31 to the other and
may be sufficiently sized to sit in the inlet 22. In this
embodiment, the first position of the magnetic stopper 30 is
characterized in that the axis of the bore-hole 310 is miss-aligned
with respect to the axis of the container 20 and the magnetization
of the material of the magnetic stopper 30 such that flow of the
pressurized fluid through the inlet 22 and the outlet 23 is
blocked. Due to the position and sizing of the spherical
ball-shaped element 31 with the bore-hole 310, the magnetic stopper
normally assumes the first position. The second position is
characterized in that the axis of the bore-hole 310 is aligned with
respect to the axis of the container 20 such that the flow through
the inlet 22 and the outlet 23 is permitted.
[0033] The controllable actuator 40 is configured to generate a
magnetic field, which is operable to urge the magnetic stopper 30
to move from the first position to the second position (as in the
embodiments of FIGS. 2A, 2B and 3) or to urge the magnetic stopper
to rotate from the first position to the second position (as in the
embodiment of FIG. 4). The rotation is caused by the interplay
between the fluidic forces that tries to move water through the
bore-hole 310 and the electro-magnetic force that tries to align
the stopper magnetization with the magnetic field created by the
solenoid coil 41. In accordance with embodiments, the controllable
actuator 40 may include a solenoid coil 41, which is formed of a
conductive element that is electrically coupled to the processing
unit 141. The solenoid coil 41 is supportively coupled to the
container 20 and, where the body 21 of the container 20 is formed
as the tubular element, the solenoid coil 41 may be slid around the
outer circumference of the body 21.
[0034] With this construction, the processing unit 141 of the
control station 14 may be configured to apply current to the
solenoid coil 41. This current generates the above-noted magnetic
field, which interacts with the magnetic stopper 30 to cause the
magnetic stopper to move (or rotate) from the first position to the
second position. The processing unit 141 may execute this routine
in accordance with a predefined schedule or current conditions
(i.e., during a dry spell, the amount of time the magnetic stopper
30 is urged toward the second position is increased so as to permit
a larger amount of the pressurized fluid to flow through the outlet
23). Moreover, the current applied to the solenoid coil 41 may be
provided as DC or AC. In the former case, the magnetic stopper 30
is continuously urged toward the second position whereas, in the
latter case, the magnetic stopper 30 oscillates between the first
and second positions.
[0035] In accordance with alternative embodiments and, with
reference to FIG. 5, a controllable emitter with variable rate
emitter feedback (CEVREF) 50 is provided. In this case, the CEVREF
50 includes first and second containers 51 and 52 disposed on
opposite sides of the corresponding drip line 11. Again, the
corresponding drip line 11 may be disposed substantially
horizontally as described above with the first and second
containers 51 and 52 disposed substantially vertically upwardly and
downwardly from the corresponding drip line 11, respectively. The
first and second containers 51 and 52 are each provided as tubular
elements, but the first container 51 may be closed at its distal
end 510 whereas the second container 52 is open at its distal end
520. The CEVREF 50 further includes a chamber 53, a spring-loaded
piston 54 and a linear displacement sensor 55. The chamber 53 is
fluidly coupled to the open end 520 of the second container 52 and
has a lower surface 530 with an opening defined therein. The spring
loaded piston 54 is operably disposed in the CEVREF 50 to be
movable in the substantially vertical direction with respect to the
corresponding drip line 11.
[0036] The linear displacement sensor 55 is coupled to both the
first container 51 and the spring-loaded piston 54 and is
configured to determine a vertical position of the spring-loaded
piston 54. In accordance with embodiments, the linear displacement
sensor 55 may include an encapsulated magnet 550, which is
encapsulated in the spring-loaded piston 54 and a magnetic field
sensitive sensor, such as a giant magneto-resistive (GMR) sensor
551.
[0037] With this construction, the CEVREF 50 is controllable in
accordance with the readings of the linear displacement sensor 55.
That is, as the pressurized fluid flows through the corresponding
drip line 11, the pressurized fluid will push down on the
spring-loaded piston 54. Thus, the higher the flow rate of the
pressurized fluid, the greater the linear displacement of the
spring-loaded piston 54 and the further the encapsulated magnet 550
will be pulled from the GMR 551. An output signal of the GMR 551
may be receivable by the control station 14 and will be calibrated
as a function of sensor-magnet position. A drip rate of the CEVREF
50 is thus controllable by varying the pressure of the fluid in the
corresponding drip line 11.
[0038] In accordance with further embodiments, the spring-loaded
piston 54 may be formed of magnetic material and the CEVREF 50 may
further include an additional controllable actuator 56. The
controllable actuator 56 may be provided as a solenoid coil 560
that can be wrapped or slid around the outer circumference of the
chamber 53. As described above, the processing unit 141 can apply
DC or AC to the solenoid coil 56 to urge the spring-loaded piston
54 formed of magnetic material toward the open end 520 of the
second container 52 or the lower surface 530. Such effect can
either block the flow of the pressurized fluid out of the chamber
53 or encourage an increased amount of the pressurized fluid to
flow out of the chamber 53.
[0039] In accordance with further aspects of the invention and,
with reference to FIGS. 6-8A and 8B, a drip irrigation system 100
is provided. The drip irrigation system 100 includes a diverter
line 101 and drip irrigation systems that are joined together at
the beginning and at the end of the drip irrigation line. The drip
irrigation system 100 further includes drip irrigation lines 102,
which are similar to the drip lines 11 described above, and
T-junctions 103. The drip irrigation lines 102 are disposable
substantially in parallel with the diverter line 101 and are formed
to define irrigation segments along their respective longitudinal
lengths. The pressurized fluid contained in the diverter line 101
is provided to the drip irrigation lines 102 and flows outwardly
through irrigation holes defined in the drip irrigation lines 102.
In some cases, each of the drip irrigation lines 102 may have
lengths that can be adjusted according to spatial resolution of
sensing zones.
[0040] The T-junctions 103 are each interleaved between adjacent
ones of the drip irrigation lines 102. As shown in FIG. 7, each
T-junction 103 includes a three-way line 110, which is coupled to
the diverter line 101, a check valve 120 and a controllable valve
130. The check valve 120 is operably disposable between the
three-way line 110 and a downstream end of an upstream one of the
drip irrigation lines 102 to permit fluid flow in only a forward
direction (see the arrows in FIG. 6). As such, the check valve 120
prohibits fluid flow in the reverse direction wherein fluid can
only flow through the drip irrigation lines 102 in the forward
direction. The check valve 120 can include a simple mechanical flap
that is opened/closed by fluid pressure or a spring-loaded nozzle
that is actuated by the pressure of the fluid in the drip
irrigation line 102. The check valve 120 may also include a
solenoid valve that is selectively opened/closed in a manner
similar to the controllable valve 130 as discussed below. In any
case, the check valve 120 is complemented by the controllable valve
130 that is selectively opened/closed as described below.
[0041] The controllable valve 130 is operably disposable between
the three-way line 110 and an upstream end of a downstream one of
the drip irrigation lines 102. In that position, the controllable
valve 130 is operable in a first mode and a second mode. In the
first mode, the controllable valve 130 permits fluid flow in only
the forward direction (as illustrated by the arrows in FIG. 6). In
the second mode the controllable valve 130 prevents the fluid flow
in the forward direction.
[0042] In accordance with embodiments, the controllable valve 130
of each of the T-junctions 103 may include a solenoid valve 140
where the solenoid valve 140 is operably coupled to, for example
the control station 14 described above. In these cases, the control
station 14 is configured to apply a current to the solenoid valve
140 or not apply the current to the solenoid valve 140 such that
the controllable valve 130 operates in the first mode or the second
mode, respectively. The determination of whether to apply the
current or not may be made by the control station 14 based on a
predefined irrigation schedule defined in accordance with a
predefined temporal resolution and/or historical data or current
atmospheric conditions. In some cases, the control station 14 can
issue commands to individual controllable valves 130 to hereby
control an amount of fluid delivered to an area proximate to the
corresponding controllable valves 130.
[0043] Each of the solenoid valves 140 may be configured to
acknowledge receipt of a command to open or close from the control
station 14. In addition, each of the solenoid valves 140 may be
configured to report back to the control station 14 that a received
command was performed or executed. Along with signls from sensors
relating to current atmospheric and soil condition, these reports
from the solenoid valves 140 may be employed by the control station
14 in a closed loop feedback control system.
[0044] In accordance with further embodiments and, as shown in
FIGS. 8A and 8B, the drip irrigation lines 102 may be disposable on
both sides of the diverter line 101 such that additional area can
be covered by the drip irrigation system 100. In these embodiments,
multiple ones of the T-junctions 103 may be disposable at similar
axial locations along the diverter line 101 and two or more drip
irrigation lines 102 may be coaxial with one another at each of
those similar axial locations. In the particular embodiment
illustrated in FIG. 8A, the irrigation holes of each of the drip
irrigation lines 102 at any one axial location of the diverter line
101 may be oriented in opposite directions so as to spray
pressurized fluid over twice the proximal area.
[0045] In any case, for any section of irrigated area associated
with a particular drip irrigation line 102, pressurized fluid will
flow outwardly through the irrigation holes only when the
controllable valve 130 is opened. Thus, an amount of irrigation in
that section is controllable by adjusting the time the controllable
valve 130 is open and knowing the number of emitters per segment
and their respective emission rates. Moreover, one or more
controllable valves 130 can be opened and closed at the same time
such that they can have a common control cycle. In addition, the
drip irrigation lines 102 may be moved across a field and the
controllable valves 130 at various sections can be activated or
deactivated (i.e., controllable valves 130 are identified as being
activated where they have an "O" and as being deactivated where
they have an "X", as shown in FIG. 8B) at various times and for
various time periods. In this way, various sections of the field
can be irrigated at various intervals and by amounts of fluid that
are appropriate for current conditions at those sections.
[0046] At the upstream and downstream ends of the drip irrigation
lines 102, the drip irrigation lines are coupled to the diverter
line 101 and a single controllable (i.e., solenoid) valve may be
provided at the far end of the diverter line 101 and would be
normally closed. These valves will stop water from escaping from
the drip irrigation lines 102 but will be opened when the system
has to be flushed to be cleaned from debris and organic material.
For flushing, a command is issued to all of the controllable valves
130 (i.e., all of the solenoid valves 140) to stay opened and water
is pumped at high pressure through the drip irrigation lines
102.
[0047] With reference to FIGS. 9A and 9B, irrigation lines such as
the main irrigation lines 11 and 101 described above are commonly
fitted with replaceable nozzles or emitters (hereinafter referred
to as "emitters") that are pressure compensated and can have the
same drip rates. The typical drip rate (hereinafter referred to as
"emission rate") would be between about 0.25 gph (gallons per hour)
up to about 8 gph. The amount of water delivered by a system using
such features can be calculated by multiplying the emission rate
with time. Thus, a 2 gph emitter that is operated for 2 hours will
emit the same amount of fluid as a 1 gph emitter that is operated
for 4 hours. As such, the same amount of fluid can be delivered by
choosing a higher emission rate emitter that is operated for a
short time or by operating a lower emission rate emitter for a
longer time.
[0048] In accordance with aspects of the invention, an irrigation
system 200 is provided. The system 200 includes a main water supply
line 201 and one or more lateral driplines 202 fluidly coupled to
the main water supply line 201. Each of the one or more driplines
202 is divided into segments (or zones) 203 that are separated from
one another by a controllable valve 204, such as a pressure
regulating or solenoid valve 2040. The controllable valve 204 can
be actuated (i.e., turned on and off) by a voltage pulse issued
from control station 14 similar to the manner described above.
[0049] As shown in FIG. 9, each of the one or more driplines 202 is
equipped with a plurality of emitters 205 such that each dripline
202 has a group of emitters 205 in each zone. Each emitter 205 is
activated when the controllable valve 204 associated with the
corresponding zone is actuated or turned on. The one or more
driplines 202 are arranged such that groups of emitters 205 for
each one of the driplines 202 may be provided in each zone.
[0050] The one or more driplines 202 are further arranged such that
higher rate emitters 205 are disposed toward the end of the
corresponding dripline 202, which is remote from the main water
supply line 201. The lower emission rate emitters 205 are then
disposed closer to the main water supply line 201. Thus, in zone 4,
the emitters 205 have a high emission rate, in zone 3, the emitters
205 have a medium high emission rate, in zone 2, the emitters 205
have a medium low emission rate and, in zone 1, the emitters 205
have a low emission rate. As such, in order to maintain a uniform
amount of fluid delivered to zones 1-4, the emitters 205 in zone 4
need to be activated for the shortest time, the emitters 205 in
zone 3 need to be activated for the next shortest time, the
emitters 205 in zone 2 need to be activated for the next shortest
time after that and the emitters 205 in zone 1 need to be activated
for the longest time. For this to occur, the controllable valves
204 (V4) between zones 3 and 4 need to be opened for the shortest
time, the controllable valves 204 (V3) between zones 2 and 3 need
to be opened for the next shortest time, the controllable valves
204 (V2) between zones 1 and 2 need to be opened for the shortest
time after that and the controllable valves 204 (V1) between the
main irrigation line 201 and zone 1 need to be opened for the
longest time.
[0051] In some cases, it is to be understood that it will not be
necessary or desirable to provide a uniform amount of fluid to each
of the zones 1-4. In such cases, time multiplexing may be employed
to vary an amount of fluid delivered to some of the zones but not
others (i.e., to provide a relatively large amount of fluid to a
central area and relatively small amounts of fluid to outer areas).
For example, if the controllable valves 204 in zones 1-4 have
respective emission rates of 0.5, 1, 2, 4 gph, "open" time units of
8, 4, 2, 1 would be allocated to the controllable valves 204 in
order to have a same amount of water delivered to zones 1-4. Here,
as noted above, the amount of time the lowest-rate controllable
valve 204 is kept open is the longest in the system since fluid has
to flow through that segment.
[0052] To put twice as much fluid in zone 2 with the same
controllable valve 204 configuration noted above, requires a time
sequence 8, 8, 2, 1. If, however, it is desired that three times as
much fluid in zone 2, it may be necessary to decrease the emission
rate of the controllable valve 204 of zone 1 to 0.25 gph. Now, the
sequence of controllable valves 204 will be 0.25, 1, 2, 4 and the
"open" timing would be 16, 12, 2, 1.
[0053] In accordance with embodiments, different or multiple
driplines 202 can be grouped together and controlled to thereby
create "variable rate irrigation" zones. In such an approach, the
"variable rate irrigation" zones can be created continuously based
on information provided by monitoring stations that would delineate
the "variable rate irrigation" zones and specify the amount of
fluid needed in each corresponding location. Such feedback
information can be provided by soil moisture sensors that would
monitor the water content in the soil, satellite sensing to monitor
the evapo-transpiration of the associated canopy or canopy sensors
to measure local water content. Any of the sensing approaches will
have a spatial and temporal resolution determined by the detection
methods and the resolution will be matched by the length of drip
lines segments and by updating the irrigation schedule. For common
satellite imagery like LANDSAT, the spatial resolution will be
about 15 m and the temporal resolution will be 7 day.
[0054] As shown in FIG. 9B, the multiple controllable valves 204
may be coupled to the control station 14 via gateways 206. With
such a configuration, the control station 14 is provided as a
master unit that is responsible for irrigation scheduling as well
as other functionalities and the controllable valves 204 are slave
elements subject to the control station 14. The gateways 206 may be
provided as wired or wireless elements.
[0055] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one more other features, integers,
steps, operations, element components, and/or groups thereof.
[0056] The corresponding structures, materials, acts, and
equivalents of all means or step plus function elements in the
claims below are intended to include any structure, material, or
act for performing the function in combination with other claimed
elements as specifically claimed. The description of the present
invention has been presented for purposes of illustration and
description, but is not intended to be exhaustive or limited to the
invention in the form disclosed. Many modifications and variations
will be apparent to those of ordinary skill in the art without
departing from the scope and spirit of the invention. The
embodiments were chosen and described in order to best explain the
principles of the invention and the practical application, and to
enable others of ordinary skill in the art to understand the
invention for various embodiments with various modifications as are
suited to the particular use contemplated.
[0057] While the preferred embodiments to the invention have been
described, it will be understood that those skilled in the art,
both now and in the future, may make various improvements and
enhancements which fall within the scope of the claims which
follow. These claims should be construed to maintain the proper
protection for the invention first described.
* * * * *